WASHINGTON -- David Brooks of The New York Times wonders whether, as a lifelong Mets fan, he is morally permitted to jump ship and pledge allegiance to the new team of his (relatively) new hometown, the Washington Nationals (nee Montreal Expos).

It's a charming dilemma, but it raises a more fundamental question: What is with this rooting business in the first place?

It is one thing to root for your son's Little League team. After all, he is your kid, and you paid for his glove -- and uniform, helmet, bat, and, when he turns 9, cup. You have a stake in him, and by extension his team.

But what possible stake do grown men have in the fortunes of 25 perfect strangers, vagabond mercenaries paid obscene sums to play a game for half the year?

The whole thing is completely irrational. For me, this is no mere abstract question. I have been a baseball fan most of my life. I could excuse the early years, the Mantle-Maris era, as mere childish hero worship. But what excuse do I have now? Why should I care about these tobacco-spitting, crotch-adjusting multimillionaires who have never heard of me and would not care if I was dispatched to my maker by an exploding scoreboard?

Why? I have no idea. True, my interest cooled for a decade when, at age 15, I discovered girls. But then one day, living in Boston and almost totally indifferent to the game, life took a fatal turn. I tuned in to the 1975 World Series and happened upon the single greatest game ever played. By the time Game 6 was over, I was hooked. Again.

Carlton Fisk's 12th-inning home run dance was just the icing. I was hooked by the improbable glory of what came before: Dewey Evans' spectacular catch off Joe Morgan in the top of the 11th, George Foster nailing Denny Doyle at the plate in the bottom of the ninth, and the most improbable home run I'd ever seen: Bernie Carbo's 3-run pinch tater -- after a couple of flailing swings -- to tie the game in the bottom of the eighth with two outs, two strikes and hopelessness in the air.

That did it. For the next 10 years, I was a fan again -- straining at nights to catch West Coast late games on a Sony transistor, checking box scores first thing in the morning.

Then came the 1986 World Series and the Great Buckner Collapse. At that point, I figured I'd suffered enough. I got a divorce. Amicable, but still a divorce. With a prodigious act of will, I resolved to follow the Sox -- but at an enforced distance. I refused to live or die with them. Which is how I got through Grady's Blunder -- leaving Pedro in too long -- in Game 7 of the 2003 Red Sox-Yankees playoff.

It was a hard fall for Sox fans, but I came through it beautifully -- feeling delighted, indeed somewhat superior, at my partial emancipation from the irrationality of fandom (far more troubling than the pain). Thus a free man, almost purged of all allegiance, I watched with near-indifference as the Montreal Expos moved to Washington. Little did I know.

The Washington Nationals are born. I do not know a thing about them. I do not know a single player on the team. I have no residual allegiance to them -- even though I grew up in Montreal and remember well their opening 1969 season at absurdly chintzy Jarry Park -- because I never cared about the Expos.

But it is a new home team. And I am a bit curious. So I'm listening to their second game, a come-from-behind win in which no-name center fielder Brad Wilkerson hits for the cycle. Next day, a nifty comeback: Jose Vidro hits a game-winning homer in the 10th.

I'm beginning to ask the Butch Cassidy question: Who are those guys? Then another comeback, another game-winning dinger, this time by Jose Guillen, a refugee from the Anaheim Angels, shipped out after, let us say, an altercation with his manager. And then yet another surprise victory against the fearsome Atlanta Braves, a ridiculously impossible comeback with two outs in the ninth.

Presto. It is 1975 all over again. I begin to care. I want them to win. Why? I have no idea. I begin following day games on the Internet. I've punched not one but two preset Nationals stations onto my car radio. I'm aghast. I'm actually invested in the day-to-day fortunes of 25 lugheads I never heard of until two weeks ago.

This is crazy. I've relapsed, and I like it so much I've forsworn all medication.